The HD battery (27-F) was standard on the Boss and 429 cars and was optional on all other models. There were two Torino sourced battery trays used on the Mustang. DOOZ-10732-A for the standard battery and DOOZ-10732-B for the HD battery.
The dimensions for the 24 series battery (W) 6 13/16" (L) 10 3/4" (H) 8 61/64"
The dimensions for the 27 series battery (W) 6 13/16" (L) 12 1/2" (H) 9 9/64"

Steve

No Officer...I really don't know how fast I was going, my speedometer stopped at 140!